Circuit breaker



Aug. 14, 1956 5 SheetsSheet 1 Filed July 25. V 1950 m 4 M I m 5 6 f f m v m. w r B 2 N 5 7 35 4 m 3 A I 3 I/ 4 /v %4 2m u 2 a 3 Z .1 H w 2 3 9 H 7 w H 3 .A h z v J 0 B 5 .2 1 4 A. B. RYPlNSKl CIRCUIT BREAKER Aug. 1956 3 Sheets-Sheet 3 Filed July 25 1950 l'mventor 7/4 III Gttorneg CIRCUIT BREAKER Albert B. Rypinski, Laureltou, N. Y., assignor to Murray Manufacturing Corporation, Brooklyn, N. Y., a corporation of New York Application July 25, 1950, Serial No. 175,671

3 Claims. (Cl. 200-89) The invention herein disclosed relates to a circuit breaker of nominal rated capacity, such for example, as may be used in homes, offices and the like.

An object of the invention is to provide a circuit breaker of the kind mentioned that is relatively smaller in overall dimensions than like circuit breakers now in use. Another object of the invention is to simplify the construction and operating parts of an electro-rnagnetic circuit breaker of the kind mentioned. A further object of the invention is to reduce the cost of manufacture of such circuit breakers.

The foregoing objects, and certain advantages that will hereinafter appear, are realized in the circuit breaker embodying the invention that is disclosed in the accompanying drawing and described below, from which description a clear understanding of the invention may be had.

The drawings include:

Fig. 1, which is a side elevation of a circuit breaker embodying the invention;

Fig. 2, which is a plan of the same;

Fig. 3, which is a side elevation of the circuit breaker, with part of the case removed and taken on the line 33 of Fig. 2, the figure being on enlarged scale to more clearly illustrate the operating parts;

Fig. 4, which is a sectional plan view of the same taken on the line 4-4 of Fig. 3;

Fig. 5, which is a sectional elevation, similar to Fig. 3 but showing certain of the mechanism in section;

Fig. 6, which is a sectional plan taken on the line 6-6 of Fig. 5

Fig. 7, which is a transverse, sectional elevation, taken on the line 7-7 of Fig. 5;

Fig. 8, which is a transverse sectional elevation, taken on the line 8-8 of Fig. 5;

Fig. 9, which is also a transverse sectional elevation taken on the line 9--9 of Fig. 5

Fig. 10, which is a side elevation, with part of the case removed, showing the circuit breaker in the on position thereof; and

Fig. 11, which is an isometric view of the stationary contact of the circuit breaker.

The specific circuit breaker illustrated in the drawing is of the kind that utilizes an electromagnet to trip the breaker on continued overload and short circuit. In general, the circuit breaker includes a case A of insulating material that encloses the contact and operating parts; a stationary contact B; a movable contact C, movable toward and away from the stationary contact; a manual operating lever D; a toggle connection E between the operating lever D and the movable contact arm C; an electromagnet F; and a cooperating armature G for tripping the toggle on continued overload and short circuit. The parts of the circuit breaker are held together in assembled relation by interlocking connections with the case.

The case A consists of two longitudinally divided halves 1 and 2. In the assembled circuit breaker, the two halves of the case are held together by rivets 3. When the States Patent ice casing is assembled, there is a slot 4 through the top thereof through which slot, the operating lever D extends. At each end of the case, there is a recess in which there are terminal screws 5 and 6 for connecting the circuit breaker to the stationary contact B and the electromagnet, respectively.

The stationary contact B is shaped as shown. It inciudes a contact portion 7, a spaced terminal portion 8 and a portion 9 connecting the contact portion and the terminal portion. The wall 9 includes an inclined section 10 and a vertical section 11. The terminal portion is provided with a threaded opening 12 into which the terminal screw 5 is received. At opposite edges, the wall 9 is notched as at 13 and 14. Side walls and 16 form, with the contact B, a housing into which the contact arm extends. The walls 15 and 16 have tongues which extend into the notches 13 and 14 to retain the walls in position to form a housing with the contact B. These side walls 15 and 16 desirably consist of fibre pieces.

The movable, operating mechanism of the circuit breaker is mounted upon an L-shaped frame that includes a leg 17 that is parallel to the base of the case of the circuit breaker and a leg 18 extending at right angles to the leg 17. From adjacent the end of the leg 18, two spaced bracket arms 19 and 20 extend from opposite side edges of the leg 18. These bracket arms are integral with the frame. A pivot pin 21 extends through the brackets 19 and 20 and into recesses 22 and 23 in the sections 1 and 2 of the case. A pair of cars 24 and 25 extend from the leg 17 of the frame. These ears have openings therethrough and a pin 26 extends through the ears and into recesses provided therefore in the casing. By virtue of the pivot pin 21 and pin 26, the frame is held in position in the case.

The actuating lever D is pivoted on the pivot pin 21, between the brackets 19 and 20. The lever has a slotted or bifurcated section 27. A pivot pin 28 extends between the arms of the slotted or bifurcated section 27 of the actuating lever. A pair of links 29 are pivoted at one end of the pivot pin 28 and at the other end, by a pivot pin 30, to one end of a link 31. The link 31 is bifurcated and at its opposite end receives the contact arm C which is pivotally secured thereto by a pivot 32. The links 29 and 31 thus form a toggle joint or connection between the actuating lever D and the contact arm C. The links 29 are provided with extensions 33 having flat faces 34 extending radially of the axis of the pivot and constituting detents. These detents cooperate with a latch 35. The latch is in the form of a U-shaped wire that extends through and is journaled in the link 31. Between the arms of the link 31 and adjacent the faces 34 of the extensions 33, the Wire is semicircular in cross section. The latch is biased towards latching position by a light spring 36 which is wound about the pivot pin 30 of the link element and secured to the link 31 and having an extension which engages the leg a of the latch. When the circuit breaker is in the closed or operating position (Fig. 10), in which the contact arm C engages the stationary contact, the detent 34 of the links 29 engage the edge of the fiat surface of the latch 35. Under these circumstances, the contact arm is held by the toggle in contact with the stationary contact.

The contact arm C is provided with a contact block 37 that is positioned to cooperate with the contact portion 7 of the stationary contact B. The contact arm is pivoted between its ends and on the side thereof opposite the contact face 37, it is provided with a slot 38 in which there is received a looped portion 39 of a spring 40. The spring 40 includes a portion 41 that is wound about the pin 26 and the ends thereof engage the legs 17 of the frame. The looped portion 39 enters the slot 38 and engages the arm C as a pivot, moving with the arm so that in effect it constitutes a floating pivot. The spring urges the arm C away from the stationary contact B. That is, away from the contact surface 7 of the stationary contact B. When the latch 35 is actuated to release or trip the toggle, the spring 4% moves the contact arm C away from the contact surface 7 of the contact B as shown in Figs. 3 and 5. Also, the looped portion 39 of the spring 40, acting as a floating pivot, urges the contact arm about the pivot pin 32 and towards the contact surface 7 of the stationary contact.

With this arrangement, when the circuit breaker is moved to the On position by actuating the lever D, the contact surface 37 of the contact arm C engages the contact surface of the contact B in a wiping action. .In addition, by virtue of this floating spring pivot arrangement, any wear on'the contacts is taken up by the action of the loop portion of the spring 39. The loopportion 39 tapers inwardly so that at the pivotits width is slightlyrnore than the thickness of the contact arm C. This prevents side movement of the contact arm .atthis point. The end 41 of the contact arm is substantially L- shaped and in the Off position ofthe circuit breaker, it stops against the frame (Figs. 3 and 6).

The toggle E, when in the On position of the circuit breaker, may be tripped manually by operating the actuating lever D or by the current actuated means consisting ofthe electromagnet F and the armature G. The electromagnet F consists of a coil 42 wound about a core 43. Desirably, the core consists of a hollow tube in which there is a movable core, the tube being filled with oil and the core'being resiliently urged towards one end of the tube. This construction of a core is old in the art and has not therefore been illustrated in detail in the drawings. The core 43 extends through an opening provided therefore in the leg 17 of the frame, and extends parallel to the-leg 18 of the frame. At the end thereof, adjacent the free end of the leg 18, the core 43 is provided with a pole piece 44. The pole piece 44 is circular and riveted to the end of the core. It is provided with diametrically opposite extending lugs 45 and 46 which extend into slots in the sides of the casings 1 and 2, respectively. The extensions 45 and 46 engaging in the slots in the case and the core extending through the opening in the leg 17 of the'frame position the core in the frame without the necessity of soldering the core to the frame.

The armature G is positioned to be attracted by the electromagnet F. It has a circular section 47, normally slightly spaced from the pole piece 44 of the electromagnet. The armature is pivoted on the pivot pin 21 on which the actuating lever D is also pivoted. An arm 436Xffi-Ild8 from the armature and with the armature forms a bell-crank lever. The arm 48 is positioned so that when the armature 47 is attracted tothe pole piece 44, it engages the arm 35a of the latch 35 and actuates the latch to trip the toggle. The armature 47 is resiliently urged away from the pole piece 44 by a spring 49 that is wound about the pin 26. One end of the spring 49 engages a lateral extension 59 on the arm 48 which lateral extension (Fig. is positioned to engage the arm 35a of the latch 35, the other end 51 of the spring 49 is engaged by a tooth of a stationary ratchet 52. The ratchet 52 is provided for the purpose of adjusting the pressure of the spring on the armature. A bias adjustable stop 53 is trapped in the case, that is, it is held and supported directly by the case. It is received in coinciding slots in the two halves of the case. The top includes a leg 53 that engages the armature to limit the separation of the armature from the pole piece 44. By bending the leg 53 towards or away from the armature, the amount of separation of the armature from the pole piece 44 may be adjusted.

The coil 42 of the electromagnet is connected at one end to a terminal 54 into which the terminal screw 6 is threaded. The other end of the coil is connected by a fiexible wire or pigtail 55 to the contact arm C. Thus current flowing through the circuit breaker, in the closed position thereof, flows through the coil 42 of the electromagnet.

From the foregoing description of the embodiment of the invention illustrated in the drawing, it will be seen by those skilled in the art that there are several novel features embodied in the construction which permit the making of a circuit breaker ofrelatively small overall dimensions. Some of these features include the utilization of the spring for the purpose of moving the movable contact away from the stationary contact and also acting as a floating pivot for the contact arm to effect a wiping action of the contacts and for taking up any wear in the contacts. Also, the arrangement by which the armature and the actuatinglever or handle are pivoted on a common pivot reduces the complexity of the construction and makes it feasible to make the armature of a single steel stamping. Heretofore, it has been necessary to make thearmature of steel at the point where the coil attracts it and brass at the trip point. In the arrangement disclosed, the steel end of the combined arm is far enough away from the coil so that stray magnetism does not prevent proper functioning. The arrangement of trapping the pole piece in slots in the case, avoids the necessity of soldering the core tube to the frame. Finally,.as the brass adjustment piece for the armature is trapped in and directly supported by the case, it is no longer necessary, as was necessary in previous designs, to weld the adjustment piece to the frame. It is also to be noted that, in the construction disclosed, the two halves of the case are interlocked with tongue and groove joints. With this arrangement, live parts can be touching thejoint inside, grounded parts touching the part outside, and still the necessary spacings are there even though the walls are thinner than the required spacing.

In Fig. 3, the circuit breaker is shown in the position in which the contacts 7 and 37 are separated. When the operating lever D is moved to the left, as seen in Fig. 3,:the link 29-is moved downward, and through the ,pivot 30, moves the link 31 downward against the action of the spring 40. When the pivot 23, by which thelink-29 is connected to the operating handle, reaches the position shown in Fig. 10, the latch 35, under the actionof the spring 36, engages the flat faces 34 of the extensions33 on the links 29. The engagement of the latch 35 with the faces 34 restrains movement of the links 29 and 31 under the action of the spring 40. Upon a .continued overload or short circuit, the armature 47 is attracted by the electromagnet F and moves about the ,pivot 21. The arm 48 extending from the armature engages the arm 35a of the latch 35 and actuates-the latch to release the extensions or detents 33. The links 29 and 31 then move in a direction to move the contact 37 awayfromthe contact 7.

.Figs. 1 and 2-of the drawing show the actual size of a circuit breaker constructed in accordance with this invention. It is considerably smaller in overall dimensions than like electro-magnetic circuit breakers.

It will be obvious that various changes may be made by those skilled in the art in the details of the embodimentrofthe invention illustrated in the drawings and described above within thescope and principle of the invention as expressed in the appended claims.

I claim:

1. In a circuit breaker of the kind described, the combinationcomprising a casing, a stationary contact within the casing, a movable contact arm movable toward and 'awayfrom saidstationary contact, an actuating lever extending through the casing for manually effecting movementof said contact arm, a toggle connection pivotally conneetedtosaid actuating lever and the movable contact arm between the ends thereof, a contact at one end .ofithe contact :arrn positioned to cooperate with the stationary contact, current actuated means for tripping the toggle, a'stationary pin-within the case, a spring for moving the contact am away from the stationary contact upon the tripping of the toggle and including a portion wound about said stationary pin and a portion engaging said contact arm at a point intermediate the pivot and the end of the contact arm opposite from the end carrying the contact, the portion of the spring engaging the arm being movable therewith, acting as a floating pivot therefor, and biasing the contact arm about the pivot in a direction to move the contact thereon towards the stationary contact.

2. In a circuit breaker of the kind described, the combination comprising a casing, a stationary contact within the casing, a movable contact arm movable toward and away from said stationary contact, an actuating lever extending through the casing for manually effecting movement of said contact arm, a toggle connection pivotally connected to said actuating lever and the movable contact arm between the ends thereof, a contact at one end of the contact arm positioned to cooperate with the stationary contact, current actuated means for tripping the toggle, a stationary pin within the case, a spring for moving the contact arm away from the stationary contact upon the tripping of the toggle and including a portion wound about said stationary pin and a portion engaging said contact arm at a point intermediate the pivot and the end of the contact arm opposite from the end carrying the contact, the portion of the spring engaging the arm being movable therewith, acting as a floating pivot therefor, and biasing the contact arm about the pivot in a direction to move the contact thereon towards the stationary contact, and a stop for limiting the movement of the contact arm about the pivot.

3. In a circuit breaker of the kind described, the combination comprising a case, an L-shaped frame within the case having spaced brackets extending from one leg thereof and spaced ears extending from the other leg thereof, a pivot pin extending through the brackets and beyond the sides thereof, operating mechanism mounted on the pivot pin between the brackets, an electro-magnet having a core extending through an opening in the leg of the frame having the ears extending therefrom, the electro-magnet extending parallel to the leg of the frame having the brackets thereon, an end pole piece on the core having oppositely extending lugs thereon, a fixed pin extending through the ears on the second mentioned leg of the frame and beyond the sides thereof, the case having slots in the side walls thereof to receive the pivot pin, the fixed pin and the lugs on the end pole piece, whereby the assembly is positioned in the case by interengagement of the pins and the lugs on the and pole piece with the case, and an armature pivotally supported by the spaced brackets and positioned to be actuated by the electro-magnet.

References Cited in the file of this patent UNITED STATES PATENTS 300,253 Hazazer June 10, 1884 772,914 Badeau Oct. 25, 1904 939,659 Bezer NOV. 9, 1909 1,145,235 Eldon July 6, 1915 1,767,479 Roller June 24, 1930 1,812,847 Sachs June 30, 1931 2,072,932 Wilckens Mar. 9, 1937 2,352,517 Christensen June 27, 1944 2,360,922 Wilckens Oct. 24, 1944 2,617,907 Umbarger et a1 Nov. 11, 1952 

